What is Black Flick?

I am facing a black screen just a half second flick while using wired Pakistan forum. It occurs after 3 or 4 minutes delay.

What is it and are you experiencing same issue ?

"Black screen" flick of whole computer screen or just inside the browser? Which browser are you using? What are the specs of your computer? What is the speed of your internet?

It is possible that your browser tries to "repaint" the browser window after it completed downloading the webpage. Just this happened only with wiredpakistan.com or with all other websites?